(a) Field of the invention
This invention relates to cart brakes, particularly shopping cart brakes. It more particularly relates to an automatic acting brake that is actuated at a particular speed to stop the cart.
(b) Description of the prior art
It is a common problem in modern supermarkets, malls, and discount stores with large parking lots to manage shopping carts. Customers regularly use shopping carts to transport purchased goods from the store to their vehicles. Even though stores provide outdoor racks for return of the shopping carts, some customers don't bother to place the carts in the racks. The result is, because of wind or sloping parking lots, shopping carts all to frequently roll out of control to damage automobiles or inflict injuries on pedestrians in the lot. The result of this is an annual cost to retailers and insurance companies of millions of dollars, not to mention lasting injuries to customers.
Many attempts have been made to provide shopping cart brakes to eliminate this problem, and all have some broad limitations. The first being that the brake is overly complicated to construct and the second being that the brake must be actuated by the customer when it is left in the lot. The sad fact is, is that the customer cannot be relied upon to have the presence of mind to actuate the brake when they abandon the cart in the lot. The first limitation is represented by U.S. Pat. No. 3,652,103 to Higgs. This design requires photoelectric cells, electronic timers and actuators, rechargeable batteries, and actuating device at the store exit. Not only is this approach expensive and complicated to build, but difficult to retrofit to existing carts, and would be a continuous problem to maintain. U.S. Pat. No. 5,042,622 to Smith and Powers, U.S. Pat. No. 5,328,000 to Rutter and Houseman, and U.S. Pat. No. 5,199,534 to Goff are representative of the second type of limitation. That is; they require a deliberate effort on the part of the user to engage and disengage the brake.
A universal disadvantage to all the prior art, is that the brake mechanism is exposed to one degree or the other on the frame of the cart. Since, by their nature, shopping carts are physically abused, a high degree of maintenance would be required for the prior art brake mechanisms. The prior art also is vulnerable to weather conditions, since carts are commonly left outdoors, either in cart racks or singly.
There is still an unmet need for a brake that will automatically actuate without customer action, is economical to produce and install and which can be retrofit to existing shopping cart fleets.